How to crowdfund unsubsidized solar

This solar power plant is an important milestone in Spain!

Since April this year, the new 2 MW crowdfunded solar park in Spain from Som Energía has been producing power. It is unique because it has no subsidies and because the energy is sold to the retail cooperative, so the price is supplied at cost* to the investors.

Image Share by Som Energía from Alcolea plan

Image Shared by Som Energía from Alcolea plan

I’m proud of having participated in this project. It’s sustainable, doesn’t need subsidies and also a good investment. The funding will be returned with no interest, but the benefit is through the reduced energy costs in the retail monthly invoice.

Living in a flat with little space for solar panels, I find it very difficult and inefficient to install one or a couple of self-consumption solar panels. So this is a natural option, to team-up with other people to own together renewable power generation. And it avoids facing the so-called tax on the sun (discussed some time ago here).

Of course there are other investment options like Yieldcos (I have shares from Saeta Yield myself). Or simply buying 100% renewable electricity from the retailer. But helping build this small project with a cooperative feels closer to owning the plant. And power generation not only owned by big corporations is also positive, as has been the case in Germany. We can say it’s a good example of the sharing economy, too…

What other options do you see to participate as an individual in the energy transition?

*Actual calculation is 36 €/MWh, which means 6 €/MWh below the market before taxes and network charges.

Publication: PV on water channels. Avoiding evaporation through power generation

We recently got published the following article on Elsevier’s Solar Energy:

Solar Energy  Water canal use for the implementation and efficiency optimization of photovoltaic facilities: Tajo-Segura transfer scenario

Solar Energy, Volume 126 , March 2016, Pages 168-194 A. Colmenar-Santos, Ángel Buendía, Carlos de Palacio, David Borge-Diez,tRczt1q

(Note: The article can be accessed for free for a short time!)

FI 2014:  3.469

You might want to have a look at the results… Sigue leyendo

The grid as an emergency supply?

It’s official. Finally Spain has the most toll-intensive consumer power generation (what is called self-consumption) law in the world. The so-called “sun tax” is in place.

It is important to understand the worries of the regulator here;

Given the high fixed costs of the system, further reductions of electricity demand (as with self-consumption) increase the price of energy in a Grid independence cycle. The goal of increasing the toll on self-consumption is to ensure the system costs are covered, delay the implementation of self-consumption (starting in the islands and small systems), delay consumer energy storage (in fact it is also a “battery tax”) and (try to) avoid further political problems. Of course, it is not the best solution, academics and regulatory experts agree that politically fixed costs that have to be paid by all citizens shouldn’t be in the tariff but evenly paid from the nation’s bugdet (like the extra-costs for electricity in the islands).

Image by Cancia Leirissa on

“Grid Emergency Exit”                                                       Image by Cancia Leirissa on

What are the consequences? Rising prices, and the fact that fixed costs (for the contracted power) are surging, push the active consumer to look for the following solutions:

Sigue leyendo

Sea Energy Harvesting – off-shore

Of course, onshore resources are first.

Of course, it will take a long time before it’s real business, but we can start with the vision…

Where is the most “energy intense” location on earth in terms of wind, solar and other renewable sources? Is it onshore or off-shore?

Let’s see what sea energy harvesting is about…

Derived from Image by

Concept derived from Image by

There was in 2011 an interesting research I recommend here, that overlapped the irradiation and the temperature, in order to determine where solar can yield more, given the PV panels are less efficient the higher the temperature. The resulting optimal areas for generation where the Himalayas (not too accessible), the Antarctica (similar to off-shore) and regions in the southern Andes.

Sigue leyendo

Electric boats and sea energy harvesting

As commented in a recent post on renewable islands, to completely decarbonize islands, it is necessary to use renewables for electricity and heating, together with the electrification of transport. (Actually, electric mobility serves as renewable storage)

By transport I mean electric mobility on land, that is vehicles, rail, buses, but also on the sea. How can we decarbonize sea transport?

No, I’m not proposing getting our hands on the oars or going back to:

Por MKFI (Trabajo propio) [Public domain], undefined

Let’s see how…

Sigue leyendo

Surprising inventions: Sun and Wind Captors

I have decided to create a category in my blog devoted to “breakthrough” inventions that are due to revolutionize the energy landscape…

Every once in a while we get to read about products or systems that are unbelievable, and sometimes feel like a joke. My recommendation is to avoid prejudices and have an open mind for innovation. You don’t want to discard progress without a proper analysis!

Having said that, let’s have a look at this system; CSV: “Captors of Sun and Wind”, consisting in 2 solar panels, hanging on a vertical post with a balancing system…


Source: youtube

You must admit the system is kind of hypnotizing…With the typical slow balancing movement that generates sooo much power 😉

To analyze this kind of system we can consider the following: Sigue leyendo

Solar Panel 3D printing

Solar panel manufacturing has benefited from economies of scale in the race to lower the costs, following an impressive learning curve (see BNEF curve). But will the future bring the cheapest solar panels, being printed where needed from a simple and cheap device?

This is already happening in manufacturing, as described brilliantly by Chris Anderson in Makers. With technology already available for printing solar cells on paper, innovation improving efficiency and durability, is set to revolutionize solar panel manufacturing. Centralized production would be complemented by local micro-manufacturing.


Solar photovoltaics is today the best example/solution for democratization of power generation, as it allows simple and scalable self-consumption. Democratizing also the manufacturing of the panel would take it a step further, boosting solar generation capacity well above the actual double digit yearly growth.

Sigue leyendo

El solaer-opuerto de Castellón

El aeropuerto de Castellón es un tema recurrente, y un ejemplo paradigmático del boom de la construcción que actualmente está sin uso.

A día de hoy existe un juicio entre la empresa concesionaria y la generalitat, y ya no se anuncian fechas de puesta en operación.

Digo que es recurrente en conversaciones, no sólo por la guasa del “aeropuerto sin aviones”, también como ejercicio creativo; pues si no se usa como aeropuerto, ¿cómo puede aprovecharse esta infraestructura que actualmente está “en barbecho”?


Lógicamente no hay mejor aprovechamiento que el uso que le corresponde, pero qué podría haberse hecho durante estos 2 años desde que se inauguró?

Planteamientos hay de los más diversos, por ejemplo el uso de la pista para pruebas de coches, por la que el aeropuerto podría percibir unos pequeños ingresos, pero que parece no se repetirán.

Otro ejemplo es su uso público para “raves” como la que planteaba un grupo de facebook para el 24/04/11, el año de la inauguración.

Yo planteo en este post utilizar la superficie, ya nivelada y asfaltada, además de las infraestructuras de interconexión eléctrica (el aeropuerto tiene una subestación, quizás sobredimensionada de 40 MVA) para instalar una planta fotovoltaica. Ésta podría ocupar las 12,5 Ha de pista asfaltada, con estructura fija y lastrada para no realizar obra civil adicional y poder reutilizarse. Podría construirse una planta de al menos 5 MW de potencia pico, a un precio por debajo del €/Wp teniendo en cuenta que la obra civil y la fijación de la estructura pueden representar un 10% del precio y que la subestación, de 132 kV, también está ya realizada.

Además, si el aeropuerto llega a funcionar algún día, estas instalaciones pueden trasladarse a un terreno cercano y seguir aportando generación renovable al aeropuerto.

*Fuente de imagen:

Gridscale PV Lyon – Utility scale Solar – MegaPV

Organized by: ACI

Date & venue: 24-25 April 2013, Lyon

This event was an interesting opportunity for investors, developpers, technical advisors, panelists and utilities to share knowledge and ideas for the development of utility scale and MegaPV Plants.

I want to highlight and share what is a main and public topic related to utility scale Solar Plants. In order for Solar Plants to compete in the electrical market with ordinary/traditional power plants and replace progressively obsolete technologies, solar must not only be grid compliant, but start offering control power and ancilliary services. An easy guess (based on the evolution of the technology) is that in the near future these services will be provided by solar, and in general renewable plants, even improving those of traditional power plants.


Technologies that can enable better control power and services include advanced power electronics and control on the inverters, Facts, flywheels, DC powerplants, hybridation of power plants, virtual power plants, power limitation or energy storage. The advanced prediction of resource with different time lapses is key for the controllability and marketization of the generation. Reliable prediction allows the market integration specially for the services.

But it is more than a question of technology, plant and control design, also the regulatory framework is key. Grid codes have to be aligned with the interest of the grid (capacity, reliability, competition, efficiency, sustainability), and markets have to be shaped also for optimizing the transparency, reliability, efficiency and competition. For example, if control power is contracted by blocks of hours it is not as open for solar control power as if it is for single hours. Another, if tender capacities are tendered weekly, it is an entrance barrier whereas if they are tendered daily.

In summary, there are already hardware and software technologies allowing utility scale to add another benefits to sustainability and competitiveness. With appropriate regulatory frameworks, utility PV ancilliary services and control power offering will grow fast.